The invention concerns a battery module, having rechargeable and dischargeable electric energy storage cells.
One area of application of the invention is power batteries such as for example those used as power source to drive a traction motor drive in electric vehicles. Evidently, the battery module may have other applications, e.g. for the powering of fixed apparatus. These applications to power batteries make use of lithium-metal-polymer cell technologies for example. In a module, the cells are connected between two external connection terminals. A battery may, for example, consist of several modules having their connection terminals connected in series.
From document EP-B-998 778, a battery is known which contains a main computer controlling modules via a communication infrastructure during charging and discharging operations. Each module is able to operate in network mode or stand-alone mode. A module changes over from network mode to stand-alone mode in response to absence of communication connectivity with the main computer.
One of the problems found with each battery module is the ability to adapt to the different environments encountered throughout its lifetime. In particular, if each module comprises a communication infrastructure, it must be possible to use this infrastructure in different environments to avoid having to provide for a communication infrastructure per environment.
More generally, one disadvantage is that the use of the battery by different users throughout the product's lifetime is based on different material and software architectures, and leads to successive context changes which are cumbersome and detrimental to the reliability of the system. Whether the architecture is single-module (research and development, all low-voltage applications), networked multi-module (production or maintenance operations, world of industrial automation) or modules in series (high-power high-voltage applications, automotive applications), the embodiments chosen for the module in the different environments can lead to different systems which are derived from different technologies and are incompatible.
Additionally, despite the envisaged specialization, some elements common to the systems will subsist such as minimal operating and safety constraints, minimal characteristics to obtain from the end product, single form of battery module consisting of a fixed number of cells. Specializing a battery module, by providing for embedded equipment varying from one module to another, soon comes up against a dead-end. This specialization effectively assumes penalizing immobilization of the battery module or battery, management of the supplies of the different equipments, provision for management of the technical status of the set of batteries, the use of production tooling particular to each area of application, these all having prohibitive costs.
The invention sets out to obtain a battery module which overcomes the above-cited disadvantages and facilitates the utilization of one same communication infrastructure in different environments. For this purpose, a first subject of the invention is a battery module comprising:                a plurality of rechargeable and dischargeable, electric energy storage cells,        two external terminals for cell utilization,        a message communication infrastructure comprising at least one communication access with the outside of the module,        a module control unit, comprising a message processing unit, connected to the communication infrastructure to send and receive messages over the communication infrastructure,characterized in that at least two of the message systems chosen from among:        a first message system for cell characterization,        a second message system for cell forming, and        a third message system for utilization of a battery pack comprising several modules connected via their user terminals, when the pack is associated with a consumer machine for the purpose of supplying it with electric energy,        are provided in the message processing unit, which is configurable into any one of the message systems provided thereupon for utilization of the communication infrastructure.        
Therefore, with the third message system, the communication infrastructure can be used by a machine or a consumer equipment which needs to be supplied with electricity by the cells. With the first message system, the communication infrastructure enables dialogue with all the cell measuring functions provided on the module, for example for the purpose of diagnosing module status before the battery module or battery is installed on the consumer equipment. Before utilization of a module, the module is first subjected to a forming operation of its cells using a forming device. By means of the second message system, the industrial logic controller of this forming device enables use of the communication infrastructure to collect the data required for this forming from the module.
According to other characteristics of the invention:                The module control unit comprises:            means to receive information for on message system configuration,    a permanent memory (32) to store the information on message system configuration,    automatic configuration means for configuring its message processing unit as per the message system corresponding to the information on message system configuration present in the permanent memory.            The automatic configuration means comprise means to poll the value of the information on message system configuration present in the permanent memory and means for automatic selection of the message system corresponding to the value indicated by this information on message system configuration.        The communication infrastructure is of bus type, to allow connection of the external access to a communication bus.        The first message system comprises means enabling utilization of the module in a first material environment comprising the following elements connected via their message communication access to the communication bus: a device to download message systems onto the module, comprising means to send to the module the information on configuration of the message processing unit of the module as per the first message system, a charger connected to the module via a transport link transporting charge electric current for the purpose of charging its cells with electric energy, a man-machine interface to enable a user to send operating command messages to the charger and/or to the module and to receive from the charger and/or module the statuses thereof.        It comprises means to measure the voltage and current of the cells and the temperature of the module, the control unit being able to send the measurements over the communication infrastructure by at least one measurement-sending message provided in each message system.        The message processing unit comprises means to receive a message from the downloading device, conveying at least one calibration parameter for the measuring means in the second message system, and means to store said calibration parameter in a memory.        The first message system is asynchronous.        The communication infrastructure is of bus type, to allow connection of the external access to a communication bus, the second message system comprises means enabling utilization of the module in a second material environment for cell forming, comprising the following elements connected via their message communication access to the communication bus: a plurality of modules whose user terminals are not connected together, at least one charger connected to the modules via at least one transport link for transporting charge electric current for the purpose of charging their cells with electric energy and able to be placed in charge-on status or charge-off status, a forming device to form the cells of the modules comprising a discharge bank connected to the user terminals of the modules and able to be placed in discharge-on status of the module cells or discharge-off status of the module cells, the forming device comprising means to send a message of charge-on command to the charger and of discharge-off command to the discharge bank and a message of charge-off command to the charger and of discharge-on command to the discharge bank.        The message processing unit comprises means to produce at least one message from among the following messages in the second message system:            a message from the module to the associated charger carrying the charge setpoint to charge the module cells,a message from the module to the forming device carrying the statuses and alerts of the module,    the message processing unit comprises means to receive a status message sent by the charger to the module, said status message carrying the status of the charger and any possible alert of the charger, to cause the module to transition to a safe fall-back position in the event of absence of said charger status message or if said status message of the charger indicates an alert or a voltage or temperature status lying outside prescribed tolerances.            The second message system is in CANopen format.        The communication infrastructure is of bus type, to enable connection of the external access to a communication bus, the third message system comprises means allowing utilization of the module in a third material environment for cell utilization comprising the following elements connected via their message communication access to the communication bus: a plurality of modules whose user terminals are connected together, at least one charger connected to the modules via at least one transport link transporting charge electric current for the purpose of charging their cells with electric energy, a supervisor of the consumer machine.        The message processing unit comprises means to produce charge setpoints for its cells, in the third message system, intended for a charger.        In the third message system, the module is able to be configured as master module or as slave, the message processing unit of the module configured as master module comprising means to send command messages to the other slave modules, the message processing unit of the module configured as slave module comprising means to carry out command messages from the master module.        The module being master, the message processing unit comprises means to produce at least one message from among the following messages in the third message system:            a first message sent from the module to the supervisor sending at least one of the data items from among the status of the battery pack, the total voltage of the battery pack, the level of the battery pack, a maximum permitted discharge current and a maximum permitted cell regeneration current,    a second message for sending at least one alert from the module to the supervisor,    a third message for sending from the module to the supervisor the value of the current supplied by or absorbed by the pack and/or the value of the maximum temperature of the pack.            The module being master, the message processing unit comprises in the third message system a means to receive a fourth message for sending from the supervisor to the module at least one of the following:            an alert acknowledgement,    a consumption request, causing transitioning of the pack modules to active mode, and when the modules of the pack have changed over to active mode, the sending by the module of a transition-to-active-mode message to the supervisor for authorizing functioning of the consumer machine,    a request to place the modules of the battery pack on standby,    a request to shut down the modules of the battery pack.            The module being master, the message processing unit comprises means to transmit a synchronization frame for the messages of the modules in the third message system.        The communication infrastructure is of CAN bus type.        The messages of the first, second and third message systems have as order of priority for transmission on the bus:            very high priority for the message transmitting information on message system configuration,    very high priority for transmission of a synchronization frame by the master module,    high priority for transmission by the modules of alerts, data, setpoint to the charger,    high priority for transmission by the charger of a fault message or status message,    high priority for transmission of commands from the master module to the slave modules,    low priority for transmission from the master module to the supervisor of first second and third messages,    low priority for transmission of the fourth message from the supervisor to the master module.
The invention concerns also a pack of several battery modules according as described above, characterized in that the communication infrastructures of the modules are connected to a communication bus for the transmission of the messages. According to other characteristics of the invention:                The user terminals of the modules are electrically connected together to utilize the battery pack, only one of the modules is configured as master module, whereas the other modules are configured as slave modules of this master module for the messages of the third message system, so that the slave modules transmit or receive their messages of the third message system via the master module.        Each module comprises means to produce data on the functioning of the cells of the module, the master module comprises means to transmit a synchronization frame on the bus so that the modules transmit their data-carrying messages on the bus at prescribed times different from each other.        